A 60 kg woman arrives after a road traffic accident with estimated blood loss of 1000 mL. She is anxious, HR 110/min, BP 110/80 mmHg with a narrowed pulse pressure, RR 24/min, and urine output 25 mL/hr. According to the ATLS classification of haemorrhagic shock, which class does she fall into?

• A Class I
• B Class IV
• C Class III
• D Class II ✓

Explanation

Class II haemorrhagic shock corresponds to 15 to 30% blood loss, roughly 750 to 1500 mL in a 70 kg adult. Typical findings are tachycardia over 100, narrowed pulse pressure from increased diastolic tone due to catecholamines, tachypnoea, anxiety, and urine output of 20 to 30 mL/hr, all present here. Systolic BP remains normal, which is why blood pressure is a poor early marker. Class III shows hypotension and urine output below 20 mL/hr, and Class IV adds marked tachycardia above 140 and mental obtundation.

Reference: ATLS Student Course Manual, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.